Process and apparatus for manufacturing soap



Aug. 30, 1932; p ws 1,874,388

PROCESS AND APPARATUS FOR MANUFACTURING SOAP Filed Sept. 20. 1928INVENTOR Pl CE M. TRA VI 43 ER 5 ATTORNEYfi Patented Aug. 30, 1932! r"rear orrics PIECE III. TRAVIS, OF RIDGEWOOD, NEW JERSEY, ASSIGNOR TOTRAVIS PRQCESS COB- PORATXON, L? JERSEY CITY, NEW JERSEY, A CORPORATIONOF DELAWARE P306338 AND APPARATUS 1 9?.- .HANUFAGTUB-EG SOAP Applicationfiled September 20, 1928. Serial No. 307,321.

This invention relates to the manufacture of soap, and more particularlyto a process and apparatus for continuously producing a marketable solidsoap product directly from its raw materials relatively instantaneouslyas compared with the present commercial practice. K

The usual soap-making operation is generally recognized as an undulyprotracted and involved procedure, and while constant efforts have beenmade to overcome these ob jectionable factors, no satisfactorilyefi'ective and commercially practical solution has been foundheretofore- The boiling or settled soap process by which soap isgenerally manufactured in present day practice, is a long drawn out andcomparatively costly operation involving the use of cumbersome equi mentand an inordinate amount of space. I of fats by this process, aplurality of prolonged stages is required, including a sub stantialprimary saponification, followed by salting out, washing, strengthening,fitting and settling. Thereafter, in the production of the vast majorityof soaps, fillers and the like are incorporated in the hot settled soap,and the mass is run into large frames to cool. As generally conducted, aperiod varying from four days to a week or thereabouts consumed incarrying out the boiling and associated stages properly, and from threeto six days in the usual frame cooling.

Formerly the so-called cold process was more widely used for soapmanufacture'but that process has been more or less generally applantedby the more effective boiling process. According to the original coldprocess, suitable quantities of strong caustic and certain fats areagitated in a crutcher for a short time, and when proper mixture hasbeen secured and saponification has progrossed to a suitable degree, theusual fillers,

' coloring material and the like are incorporated, and the reactingbatch is run into frames and allowed to stand for several days tocomplete the saponification and then to cool, the heat used in theoperation being mainly that developed by th action. The time elementinvolved does ot dilier substantially from n the saponification' that ofthe objectionaiily protracted boiling process, for from six to ten daysis ordinarily reguired for completion of the cold process.-

le from a manufacturing standpoint the process presents a less involvedand more eth'cient type of operation than does the boiling process,certain technical deficiencies practically prohibit its use in placethereof and have causcd'its general abandonment in 'favor of the latterprocess. Its major disadvantage lies in the almost invariably incompletesaponification obtained as compared with the boiling process, for evenwith the exercise of all due care, it cannot be depended upon to producesoap of suitable and uniform quality. Soap made by the ordinary coldprocess is almost always characterized by -the presence of excessiveamounts of free alkali and/or unsaponified fat, and by its tendency todiscolor and rancidify in a relatively short time.

It is the object of my invention to provide a process and apparatus bywhich a marketable solid soap of uniform and high quality, may becontinuously produced directly from its raw materials relativelyinstantaneously as compared with these recognized processes, and in amanner which is simple, practical and thoroughly effective.

According to my invention, a mixture of syrup consistency, containingthe common soaporming fats, oils or fatty acids, either individually orblended in suitable proportion, and the alkali, in which mixture isordlnarily incorporated the customary fillers such as sodium silicate,carbonate and the like, is subjected to an intense disrupting and dispersing action which increases the interfacial area and intimac ofcontact to such an extent that saponi 'cation is completed practicallyinstantaneously, with the accompanying production of anextremeglhcmogeneous and fine mixture of the soap, ers and othermaterials used, and the resulting mass is then converted preferablysubstantially immedi' ately, into very small units, in which veryaccessible form it may be quickly dried and/or cooled and/or otherwisetreated to yield a solid soap product.

' The preferred manner m which my inve tion is carried out is describedin the following specification taken in conjunction with theaccompanying drawing, in which,

Fig. 1 is a diagrammatic view of an illustrative combination ofapparatus for carry in out my invention;

ig. 2 is a fragmentary cross-section on an enlarged scale of thecocnerating working surfaces of the SEPL tification-completing ap- 30paratus used therein, for applying an intense disrupting and dispersingaction.

Referring to the drawing, and in particular to Fig. 1, referencenumerals 5 and 6 designate jacketed crutchers or agitators of ansuitable and well known type, in which t 1e raw materials for the soapare pro-mixed and treated prior to their subjection to the intensedisrupting and dispersing action, which is applied through the medium ofmill 7.

.20 These crutchers are provided in appropriate number and arealternately charged and discharged so as to assure a continuous supplyof properly pro-treated material to the mill. If desired a singlecontinuous agitator into 2 which proportionate quantities of the rawmaterials are simultaneously and continuously metered may be used inplace of the alternating crutchers. A common conduit 8 connects thecrutchers directly with the mill 7 although indirect feed through aninterposed butler or feed control tank may be used if desired.

In their passage through the mill 7 the properly mixed and pre-treatedmaterials are 5 sub ected to an intense disrupting and dispersing actionwhich increases the interfacial area and intimac of contact to such anextent that saponi cation proceeds to completion practicallyinstantaneously.

An extremely intense disruption and dis-.

persion which very efi'ectively brings about such a result is that whichis obtained for example, when a mixture of syrupy consistency containingthe constituent materials of the soap, attenuated to accessible thinfilm form, is subjected practically simultaneously to a substantial highspeed film shearing, a high speed film beating, and a violent agitationor eddying to relatively continually ex- 60 pose new surfaces of thefilm for shearing and beating.

A slmple mechanical means of applying such an action is provided byrelatively moving cooperating working surfaces conngured for example, asshown in Fig. 2. In that construction, a rotor and a. stator member,designated 9 and 11 res ectively, provide the relatively moving mem ers,the coo crating surfaces of which are both formed wlth alternating,continuous longitudinal ridges or ribs 12 and channels 13. The ridges 12terminute in substantially flat shearing faces 14 which form sharp edges15 with the sides or heater faces 16 of the ridges. The channels 13 arepreferably of smoothly curved crosssection to promote churning oreddying of the film being treated, for the purpose of continuallyexposing new surfaces thereof to the shearing and beating actions of thefaces 14 and 16 respectively. A smooth curvature of the channels neednot be rigidly adhered to however, although such conformation bestpromotes eddyiug. The sides 16 may for example form obtuse angles withthe bottom of the channel, or be otherwise contoured to provide thedesired result. 1

The rotor and stator surfaces are spaced with a very slight interveningclearance, to provide a narrow working gap 17 in which the materials aretreated in.. thin film form. A clearance ranging between .002 and .010inches 5: generally efi'ective for thorough saponification, although atparticularly high rotor speeds this upper limit maybe somewhat exceeded.

The peripheral speed at which the rotor member is operated ordinarily,ranges from 3000 ft. to 5000 ft/ min. and sometimes higher, dependingupon the width of the working gap 17, the nature of the materials beingtreated, and the intensity of effect desired.

A practical embodiment of the cooperating working surfaces of Fig. 2 ina highly efficientform is illustrated by the mill 7 of Fig. 1. This millcomprises a jacketed stator member 11 which defines an elongated chamber18 of frusto-conical form, communicating at its smaller end with a feedchamber 19 and inlet 21, and at its larger end with a discharge chamber22 and outlet 23. A rotor member 9 of a frusto-conical form similar tothat of the chamber 18 is mounted for rotation therein in closelyadjacent, non-contacting co-axial varied as desired by suitablelongitudinal adjustment of the rotor. Furthermore, mate rials fed at thesmaller end of the conical construction will be rapidy drawn towards thelarger or discharge on by the accelerating action of the increasingcentrifugal force, the degree of acceleration depending upon the slope,and the speed of the rotor. This rapid passage finds valuableapplication in large scale operation and provides adequate compcnsationin capacity for the treatment of the materials in film form rather thanas a lar e mass.

n the event the passage of the material through the working gap 17 istoo rapid for thorough subjection to the action therein, suitableretardation may be provided whereby the time or length of passage isappropriatcly est-ended. By roviding a longer gap' for example, and/orby decreasing the slope of the same, suitably prolonged subjection ofthematerials to the action in the gap may be obtained.

A positively acting means by which retardation of discharge may also besecured, without too greatly diminishing the power advantages resultingfrom the inherent centrifugal acceleration, is provided, for example, bycentrifugal impeller rooves 24, or by projecting fins if desired,disposed on a detachable or integral conical projection at the lar e endof the rotor 9. These grooves extend su stantially radially of theprojection in equi-distant relation, and terminate in the channels 13 onthe surface of the rotor proper. By suitably increasing or decreasingthe number of these grooves the retardation may be intensified ordiminished as desired. Variation of the number of operating grooves orfins may be accomplished for example, by using detachable groove fillersor detachable fins. Similar grooves 26 or other impeller faces may beprovided on a similar projection 27 at the smaller end of the rotor,

- to aid the introduction of materials into the working gap. I

Rotation of the rotor and its accompanying projections is accomplishedthrough the medium of a drivin shaft 28, which may he directly ccmiectewith a suitable motor, 30 through the medium of a flexible couplingwhich will permit longitudinal adjustment of the rotor, or which may beindirectly driven by beltv connection or the like.

The outlet 23 of the mill, which may be located at the top, bottom orintermediate points in the discharge chamber 22, is connected by meansof a conduit 29 with an apparatus for convertin or breaking up the massof material from t e mill into very small units in which form the soapis subjected to further treatment.

An exemplary and particularly effective operation of such anature,comprises converting the mass of material into a fine spray andtreating it in that form. As an illustration thereof I have shown in thedrawing the ap plication of a spray drying apparatus of suitable andwell known type.

For certain applications, the mill 7 is preferably connected with thisapparatus through the intermediary of a control tank 31, provided withan external jacket 32 and an internal coil 33, for the circulation of atemperature regulating medium, and accommodating an auxiliary mixer oragitator 34. In this tank the temperature may be regulated as desired,additional materials incorporated in the soap which are not adapted forincorporation during the saponification operation, and other conditionscontrolled asdictated by the requirements of the subsequent operation.If desired, alternating control tanks may be used in the manner of thepreliminary crutchers 5 and 6.

In other applications the mill may be connected directly with thespraying nozzles.

From tank 3]. the soap mass is delivered to spray nozzles 35- in a dryintower 36 either under pressure provided by a pump 37, or by gravity feedsupplemented by atomizing gas pressure at the nozzles, depending uponthe particular application involved. Hot air or other dryin gas isintroduced at the top of the tower tirough inlet pipe 38, and coolingair at the bottom of the tower through pipe 39. A discharge pipe llleads from the bottom of the tower to a suitable cyclone collector 42,in which the solid soap particles are separated from the eiiluent gasesand are discharged at outlet 43 indirectly marketable form.

.Specific spray drying apparatus of satisfactory application in therelation herein described, are those disclosed in U. S. patent types ofsoap stock, permits predetermined control of the glycerine content ofthe soap over a range which meets all ordinary demands. A small amountof glycerine is fre quently desired in soap because of its emol lientand lather strengthening properties, and by using suitable proportionsof fatty acids with the fats or oils when necessary, the de'siiedcontent of glycerine may be readily provided.

Mixtures of fats and/or oils with free fatty acid are not adapted fortreatment by the ordinary cold process because of the tendency of thefree fatty acid to prematurely combine with the alkali. This results inthe condition called launching which is characterized by the mechanicalenclosure of portions of unsaponified fat and/or oil, and al- -ka li bythe rapidly formed soap. These lumps are very dillicult' to disintegrateby c'rutching and their presence in the finished soap results inpoor-texture, rancidification and other undesirable features.

This bunching factor may be disregarded in the present operation, forany lumps which may form are readily disintegrated and completelyreacted by the intense disrupting and dispersing action embodied invided by the soap which is quickly formed by the free fatty acid.

Various exemplary soap stocks illustrating the wide range of mixtureswhich are worked yery satisfactorily by my process are as folows p 5Because of the very-pronounced reaction- Palm kernel oil acceleratingeiiect oi the intense disrupting stantially the theoretical quantityrequired and dispersing action comprised in my 'the ingredients,temperature regulation etc.,

process, the caustic soda and/or potash or other alkali need only besupplied in sub for the saponification of the soap stock, as indicatedfor example by the saponification value of the stock or by test runs.Where material amounts of commercial silicate filler are used however,as is usually the case in the production of laundry soaps, soap powders,bead soap, and the like, which com prise the largest proportion of soapmanufactured, it is advisable to use caustic in excess of thetheoretical to compensate for that taken up by the silicate. Mostcommercial silicate is unsaturated in this respect, the commonly used Nbrand silicate, for example, and it exhibits a tendency to absorbcaustic. The approximate" composition of the so-calledfN brand silicateis as follows: Na20-8.9%; silica29.0%; water6'2%.

The excess caustic required under such circumstances however, is ratherslight when the operation is properly conducted, for the caustic appearsto react selectively with the soap stock and the silicate does notabsorb 1t to capacity. This matter of caustic absorption by the silicatehowever, is of more advantage than disadvantage, for when materialamounts of silicate are used,the inadvertent provision of alkali inmoderate excess will not work commensurate injury in the final productbecause of the corrective action of the silicate. By the use of the lesscommon and more expensive brands of silicate which contain their maximumamounts of caustic, this absorption phase can of course be readilyeliminated, although such a procedure is unnecessary practically.

The mixed material to be introduced into the mill must be of suitableliquid consistency when supplied thereto if proper treatment is newnessto be secured. The mechanical saponification -acceierating action in theworking gap 17 is most effective, and of most eilicient application froma power consumption standpoint, when the material being treated is notthe order of commercial U. S. P. glycerine;

The general range of suitable consistencies for the mixed mass is bestdesignated as syrupy. The thickest workable consistency in this range,is determined by its amenability to eilcctive treatment and handling bythe mechanical action involved in the particular op eration. Thethinnest consistency utilizable ;is limited only by possible retardingeffect upon saponification e. g. in the reduction of 7 the consistencyby the use of water in amounts which cause undue dilution of thecaustic.

Proper consistency, as well as mixture of action in the mill. Inaddition to aliordingcontrol of the factors noted, this preliminarycrutchmg treatment serves other aluable purposes. The initial phases ofsaponification usually proceed quite readily because of the chemicalafiinity of the soap-formin ma-- terials, and it is mainly with thefinal phases and the substantial completion of the saponification thatthe greatest diilicult is encountered. For this reason it is desirableand economically expedient to cause the reaction to proceed to asuitable extent without applying any considerable amount of externalenergy, and then to utilize the intense accelerating action in the millfor the completion of the remaining stages. In accordance with thiseconomically and technically advantageous procedure, saponification ispreferably carried to a satisfactory degree, depending upon the speed ofreaction of the materials used, in

the preliminary crutching operation, with the advantages attendantthereupon of low power consumption, utilization of the heat of reactionto elevate the batch temperature, pro-regulation of consistency, etc.

The extent and manner of bringing about saponification in the crutchingoperation, will masses u foaming and securing proper consistency in thefinal clutched mass. With materials which react less readily orrelatively slowly, the preliminary crutching should be used principallyto bring about saponification to such extent as is practicahin whichoperation the incidental mixing will necessarily be very thorough, andin such cases the most advantageous temperatures are generally abovethose ordinarily dictated by the limitations of the original coldprocess. The possibility of bunching in the crutcher at hightemperatures because of too ra id reaction, with resulting mechanicalenc osure of unreacted materialbythe rapidly formed soap, presents noparticular diliiculty in the present operation, for as notedhereinbefore in relation to the use of free fatty acid-fat mixtures, itis easily remedied by the subsequent intense disrupting and dispersingaction in the mill.

The variations in temperatures, liquid content, period of crutching andsimilar operating conditions which are necessary to bring '(lifi'crcntsoap stocks and compositions to a "proper state of consistency, reactionand the like, or suitable and most economical treatment the mill, arenot great and can be readily recognized or determined by one skilled inthe art. In the matter of consistency for example, the visualobservation 01' the. mass in the crutcher usually affords a faircriterion after slight experience with the operation of the particularmill. I

Satisfactory intitial temperatures for the melted soap stock range inmost intances between 120 and 180 F., and for the caustic,

. between room temperature and 200 F., al-

the same.

though these limitations may be exceeded as the-circumstances maydictate and as will be apparent to one skilled in the art. Thetemperatures of the silicate, soda ash and similar solutions arelikewise pre-regulated as determined by the particular operatingconditions and the ultimate batch temperature desired. These solutionsserve very effectively as temperature controlling media, to correctexcessiveor deficient temperatures in the soap stock-caustic mixture.Their most general use in this respect is in the reduction of theexcessive temperatures which frequently result from rapid reaction ofthe soap stock and caustic, often accompanied by excessive swelling andfoaming, and in such application,-the silicate and soda-ash solutionsgenerally can be used at substantially room temperature of a few degreesabove or below By their addition at such temperatutes, the temperatureof the batch can be reduced economically to a proper point forsubjection to the saponification-acelerating action in the mill.

The caustic solution used should be fairly The addition of the soapstock is accom-' panied by rapid crutching, and the resulting mass isthoroughly and continuously crutched for several minutes to provide areasonably homogeneous mixture of the consistency of thick syrup, and toaccomplish a suitable saponification prior to introduction of the othermaterials. The fillers, such as sodium silicate and carbonate, trisodiumphosphate, clay etc., are then mixed into the batch before it hasthickened to a degree which would in terfere with crutching andsubsequent intro duction into the mill. Upon the addition of sodiumsilicate, the use of which is generally desirable, the mixture becomessmoother and of thinner consistency.

After a suitable period of rapid and thorough crutching to intimatel andhomogeneously incorporate the silicate, soda-ash, and/ or other fillersin the batch, the hot syrupy mass is then discharged into the conduit 8and thence into the mill 7, through inlet 21. It is desirable that thesefeed lines should be kept well filled throughout the operation inorderto exclude air.

The temperature of the mass at-the mill in let should be preferablybelow the normal boiling point of water, e. g. 140-200 F., in

order that large amounts of steam will not be formed in the mill as aresult of the heat developed therein, although the formation of,

some steam is frequently advantageous in promoting saponification anddispersion. This temperature can be readily obtained by properconduct ofthe crutching operation,

and if not, suitable correction can be secured by the use of a jacketedfeed control tank as ictional resistance to syrupy mass will be rapidlydrawn into the;

narrow conical working gap, and in accessible thinfilm form will bethere subjected to a violent disrupting and dispersing action. Asmay-best be understood by an inspection of Fig. 2, the shearing faces 14of opposite hydraulic shearing action upon ie film of liquid materialtherebctween, -etting up powerful disrupting and dispersing forces inthe film; the sides 16 and the sharp edges 15 of the ridges will providepractically simultaneously with the hydraulic shearing, a beating actionof pronounced disruptive and dispersive intensity; and the channels 13will serve to promote the violent agitation or eddying in the liquidiilm for the relatively continual exposure of new surfaces thereof tothe accompanying actions.

As a result of the action so constituted, and such other forces as maybe inherent therein in addition to those noted, the particles ofmaterial in the working gap will be practically instantaneouslydisrupted to a quasicollodial size and thoroughly and uniformlydispersed in such form, with a resultant enormous increase in theinter-facial area and intimacy of contact of the soap stock, caustic,and other materials. With such reaction accelerating conditionsprevailing, the unreacted soap stock will completely react with thecaustic, and in some instances with some of the carbonate also,practically instantaneously. The resulting mass, will, moreover, containthe soap, silicate and carbonate and /or other materials in a. state ofextremely fine and homogeneous mixture unattainable by any mixing actionheretofore used.

The particularly effective nature of such intense disruption anddispersion of the materials is clearly demonstrated when it isconsidcred, that while completion of the final stages of saponificationis ordinarily very difiicult to accomplish except by prolongedtreatment, the acceleration of the reaction obtained as noted, is somarked, that saponification is carried to completion within the fewseconds time which is required for passage through the working gap.

This specific manner of obtaining the saponification is the subject ofmy co-pending application Serial No. 307,322.

The hot mass discharged from the mill is then passed through pipe 29either directly to the spray nozzles, or into the jacketed control tank31, depending upon the requirements of the subsequent operation. In thetank 31 the temperature maybe elevated or decreased, additionalingredients admixed, and other conditions regulated as is desired ornecessary, with the temperature, consistency, liquid content, and otherconditions of the mass regulated as the nature of the subsequentoperation dictates, it is then delivered under suitable pressure by thepump 37, for example, to the spray nozzles 35 in the drying tower 36,where it is dispersed into a 'fine spray which passes downwardly throughthe tower in contact with the hot drying gas introduced through pipe 38.In its passage through the tower the sprayed material is driedthoroughly, or to the extent desired, and after the temperature of thesuspension has been suitably lowered by contact with the cooling gasintroduced at the bottom of the tower through pipe 39, the suspendedsolid particles are carried through discharge pipe 41 into the cyclonecollector l2, in which they are separated from the efiiuent gases andare discharged through outlet 43.

Where a thoroughly dried product is desired, the temperature of thegaseous sus- I pension should be maintained above the dewpoint until themoisture-laden gas has been separated in the collector. Afterseparation,

further cooling of the solid particles may then be accomplished ifdesired, by the use of a second stream of cooling gas in conjunctionwith a second cyclone collector or in any other suitable manner.

The following exemplary operation for preparing directly a marketablefinely divided soap from a specific soap stock will illustrate oneapplication of the general meth- 0d of procedure described hereinbefore.

A strong caustic solution is prepared by dissolving 12 lbs. of causticsoda (98% pure sodium hydrate) in 35 lbs. of water at room temperature,whereupon a rise in temperature to approximately 190 F. occurs due tothe heat evolved on solution. This hot solution is introduced into oneof the crutchers 5, 6 and into it is poured, with continual crutching, asoap stock blend consisting of 63.75 lbs. palm kernel oil and 2 lbs.cocoanut oil fatty acid, at a temperature of F A rapid reaction takesplace in the mixture with the evolution of an. appreciable amount ofheat, and after three or four minutes crutching a batch of thick syrupyconsistency is obtained with a temperature z-ctween 16G- 175 F. At thispoint 60 lbs. ofN brand sodium silicate at a temperature of 82 F. iscrutchcd into the batch, and directly thereafter 17' lbs. of sodiumcarbonate solution (23% soda-ash) at a temperature of 88 F.

Upon the addition of the silicate the batch becomes smoother and ofthinner consistency, and after a few minutes thorough crutching tosecure intimate incorporation of the silicate and soda-ash, with aresulting temperature e. g. of F., the hot syrupy mass is passed throughconduit 8 into the mill 7, which has been suitably preheated bycirculating steam through the stator jackets. In its rapid passagethrough the mill the mass is subjected to the intensesaponificationcompleting reaction described hereinbeforc, and itstemperature is elevated in passage to F.

In the production, for example, of the product described in the Lamontpatent hereinbeforg referred to, this hot mass from the mill is thenpassed through the control tank 31, and its temperature is quicklyraised to 220 F. in passage. From the tank 31, the heated mass isdelivered by the pump 37 to the spray nozzles 35 at a high pressure, andis sprayed into strongly preheated drying gas (500 F.) and otherwisetreated in accordance with the teachings of the patent noted to obtainthe desired product.

The particular saponification steps and ap paratus describedhereinbefore, are peculiarly. and very advantageously adapted for use inconjunction with the spray processing disclosed in the Lamont patent.The conditions of consistency and moisture content.

(usually in the neighborhood of 40% and ranging between 30% and 15%)which generally prevail in the saponification phase are such, that theresulting filled soap mass is obtained in such suitable condition forthe preparation of the Lamont product that no further adjustment ofthese conditions is necessary. The temperature at which the filled soapmass is best adapted for the spray processing (of the order of 220 F.),may be closely approximated in the mass discharged from the mill, sothat any temperature-regulation required thereafter would heinconsiderable. The saponification operation may be carried out veryeffectively at temperatures just slightly below the boiling point ofwater, and with the pressure in the mill but slightly above atmospheric,the boiling point can easily be elevated to 220 F. or above. Under suchconditions the control tank 31 may be dispensed with. i

Moreover, the finely divided product obtained by the specificcombination in my basic process of the Lamont spray drying process,exhibits markedly improved qualities, over that obtained by like spraydrying of a similarly constituted material containing soap prepared bythe boiling process, and over finely divided soap products prepared byother known methods. A finely divided, spray dried soap product made bysuch specific combination, as described hereinbefore, is for example,almost instantaneously soluble with no sedimentation of silicate orother materials, it rapidly yields a closely knit and firm lather,contains practically no free al-- kali or unsaponified soap-formingstock, is of uniform and attractive appearance, and possesses very rapidand effective detergent properties. The folubility, sedimentation andsaponification characteristics of a typical product for example, were asfollows:

Five grams of the soap dissolved completely in 100 cc. of water at 50 C.in slightly less than 30 seconds, with no stirringor agitation.

Alkali determinations showed a content of .02% free alkali (NaOH).

N0 unsaponified soap-forming stock was present.

While I have noted the eminent applicability of in basic process inspecific combinati on with the spray processing of the Lamont patent,for the production of a hollow particle of the structure described inthat patent, it is likewise applicable with markedly improved results inthe production of granular. shredded, powdered and other types of finelydivided soaps wherein sprayin exuding, or other means of converting t .esoap mass into very small units for treatment may be used.

In additionto the pronounced reduction in operating time, the markedimprovement in the product, and other novel features which result fromthis combination, of an intense disrupting and dispersin action forcomplating sauonificatien, with .a sub:equent conversion of theresulting saponified mass into the accessible form of very small unitsfor rapiddrying and/or cooling or other treatment, this combination ofsteps in my process, with the conversion to small units in substantiallyimmediate sequence to the intense disrupting and dispersing action, isof practically essential importance for the invariable production ofimproved filled soaps.

In the production of filled soaps, which usually contain sodium silicateand carbonate, intimate incorporation of the filler in the soap isessential, for with poor incorporation the soap will eliloresce andsoda-crack on aging. The ordinary crutching operation which is used forthis purpose, is at best not articularly effective, and thorough and uni.orm distribution of the filler throughout the soap is not obtainablewithout inordinately prolonging crutching, if then.

Moreover, even after apparently satisfactory incorporation, separationof the filler frequently occurs, with resulting detriment to themarketable quality and appearance of the soap. This separation usuallytakes place after the filled soap mass has been run into the frames.although it not infrequently occurs in the operations prior to framing,and the resulting solid soap cannot be economical- 1y 0: practicallytreated to correct the dithculty. The causes of such separation arerather obscure, and it has been variously ascribed to poor incorporationof the filler, crutching too hot or too cold, delayed framing, and otherfactors. The exact reason for the separation however, is usuallydifiicult of explanation, for evenwith extremely carein! repetition of asuccessful set of conditions, separation will frequently occur for noapparent reason at all. Inasmuch as filled soaps constitute the majorproportion of presentday soap production, these ditliculties are ofconsiderable importance.

In my process however, the intense dis-, rupting and dispersing actionincorporates the filler in the soap in a state of extremely finedivision and uniform distribution impossible of attainment by any degreeof ordinary crutching, with the incidental combination in a single stepof the separate saponifying and filling steps required in the boiledsoap process, and the carrying over of such an enhanced degree ofincorporation to the finished product is invariably assured by theconjoint use of the substantially immediately subsequent step of myprocess. By substantially immediately converting the homogeneous massinto very small units and rapidly drying it for example, while in suchform',the detrimental filler separation characteristic of prior methodsof production, is effectively eliminated and the extremely fine andthorough dispersion of my prior ste which provides a remarkablyhomogeneous and improved product, is obtained in every instance.

Furthermore, .the advantages of improved and uniform quality withextremely fine and homogeneous distribution of fillers and the like,obtainable by my process, are not confined to the production of soap inthe form of small units, but may likewise be extended to the productionof high grade cake soap if desired. By suitable treatment of the smallunits into which the saponified mass in my process is promptlyconverted, e. g. by suitable regulation of the temperature and volume ofthe drying gas in the spray drying operation to retain a suitable amountof moisture in the sprayedparticles, the units may readily be pressedtogether to form cakes. For this purpose use can be made, for example,of any of the well known squeezing or plodding machines, wherein soapchips are squeezed together and issue in the form of a bar which issubsequently cut into cakes for stamping and wrapping.

By the process and apparatus herein described, a practical manufacturingoperation is provided which eliminates the objectionally protracter,involved and comparatively expensive phases of the usual soap makingpractice, adequate correction c: which has long been sought.

Of major importance is the great reduction in operating timeaccomplished thereby. In this novel opera tion the time consumed in themanufacture of the product in directly marketable form from its rawmaterials is but a matter of minutes as compared with the many daysrequired in present soap practice.

Further supplementing its elimination of the inordinate time consumptionrequired in the recognized boiling and cold processes, as well as itsavoidance of their involved aspects, this novel operation suppliesvarious other deficiencies of those processes, some of which have beennoted hereinbefore, while providing added advantages.

The operation is simple in nature, involves but slight running expense.and provides a practically 100% yield. It can be carried on desired, itsvery effective treatment of pure' fatty acids, adapts it for useconjointly with the Twitchell or a similar process for obtaining freefatty acid and glycerine from the fats or oils.

In addition to this high degree of manufactnring efiiciency which theoperation presents the soap obtained thereby is of uniform an greatlyimproved quality as compared with that obtained by prior methods.Unsaponi fied soap stock and/or free alkali are absent therein, and thesoap exhibits markedly enhanced solubility, detergent properties andother desirable characteristics.

While I have described hereinan illustrative manner of carrying out myinvention and certain applications thereof, my invention is not imitedthereto or otherwise than as defined in the following claim.

I claim i The process of manufacturing filled cake soap which comprisessubjecting a mass of syrupy consistency containing the soap stock,saponifying alkali and filler to an intense disrupting and dispersingaction whereby a completely saponified mass containin the materials in afine state of division an uniform dispersion is obtained, then sprayingsaid mass while the materials are substan- 0 par tiallyrin said state,drying to a suitable de- CERIIFICATE or coamzcnou.

Patent No. 1,874,388.

I romeo M. TRAVIS.

It is hereby certified that error appears in the tirinted specificationof the above numbered patent requiring correction as follows: Page 8,line 43, for ."protracter" read orotracted; same osge, lities 08 to 110,the claim, strike out the words "to a suitable degree, and theneompactingthe droplets eonsti-' toting the spray" and insert instead thedroplets ceestituting the spray to a suitable egree and then compactingsaid units; and mar the said Letters Patent should be read with thesecorrections therein that the same may conform to the record of the casein the Patent Office.

Signed and sealed this 22nd day of November, A. I). 1932.

V J. Moore, (Sea!) Acting Commissioner of Patents.

Augtist 30, 1932.

